JPS6427231A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate the contamination of a substrate surface with fine particles and to prevent it from warping or cracking without necessity of a high temperature heat treatment and protection of the substrate surface by providing the steps of irradiating the rear face of the substrate to be formed with an element on its front surface with excimer laser and heat-treating the substrate. CONSTITUTION:The rear surface of a substrate 11 is irradiated with an excimer laser 12, the front surface is then mirror-polished to obtain a substrate 13. The energy of the laser 12 is substantially absorbed to the vicinity of the surface of the rear face of the substrate 11, and the shallow region of the front surface of the substrate is melted. The melted part is rapidly solidified to become a laser beam-like shape melted mark 14 in the vicinity of the surface of the rear face of the substrate 11 to form a distortion field for causing a gettering. Then, elements, such as a transistor and a diode, are formed on the mirror-polished surface of the substrate 13. Thus, since excimer laser light is not introduced deeply into silicon, the mark 14 is formed in a shallow depth. Thus, it prevents the substrate from warping or cracking.